title: Evaluation of a prototype flow cytometry test for serodiagnosis of canine visceral leishmaniasis.
abstract: Diagnosing canine visceral leishmaniasis (CVL) is a critical challenge since conventional immunoserological tests still present some deficiencies. The current study evaluated a prototype flow cytometry serology test, using antigens and fluorescent antibodies that had been stored for 1 year at 4°C, on a broad range of serum samples. Noninfected control dogs and Leishmania infantum-infected dogs were tested, and the prototype test showed excellent performance in differentiating these groups with high sensitivity, specificity, positive and negative predictive values, and accuracy (100% in all analyses). When the CVL group was evaluated according to the dogs' clinical status, the prototype test showed outstanding accuracy in all groups with positive serology (asymptomatic II, oligosymptomatic, and symptomatic). However, in dogs which had positive results by PCR-restriction fragment length polymorphism (RFLP) but negative results by conventional serology (asymptomatic I), serological reactivity was not observed. Additionally, sera from 40 dogs immunized with different vaccines (Leishmune, Leish-Tec, or LBSap) did not present serological reactivity in the prototype test. Eighty-eight dogs infected with other pathogens (Trypanosoma cruzi, Leishmania braziliensis, Ehrlichia canis, and Babesia canis) were used to determine cross-reactivity and specificity, and the prototype test performed well, particularly in dogs infected with B. canis and E. canis (100% and 93.3% specificities, respectively). In conclusion, our data reinforce the potential of the prototype test for use as a commercial kit and highlight its outstanding performance even after storage for 1 year at 4°C. Moreover, the prototype test efficiently provided accurate CVL serodiagnosis with an absence of false-positive results in vaccinated dogs and minor cross-reactivity against other canine pathogens.
authors.affiliation: Laboratório de Pesquisas Clínicas, Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil.
authors.forename: Henrique Gama
authors.initials: HG
authors.lastname: Ker
authors.forename: Wendel
authors.initials: W
authors.lastname: Coura-Vital
authors.forename: Rodrigo Dian de Oliveira
authors.initials: RD
authors.lastname: Aguiar-Soares
authors.forename: Bruno Mendes
authors.initials: BM
authors.lastname: Roatt
authors.forename: Nádia
authors.initials: N
authors.lastname: das Dores Moreira
authors.forename: Cláudia Martins
authors.initials: CM
authors.lastname: Carneiro
authors.forename: Evandro Marques de Menezes
authors.initials: EM
authors.lastname: Machado
authors.forename: Andréa
authors.initials: A
authors.lastname: Teixeira-Carvalho
authors.forename: Olindo Assis
authors.initials: OA
authors.lastname: Martins-Filho
authors.forename: Rodolfo Cordeiro
authors.initials: RC
authors.lastname: Giunchetti
authors.forename: Márcio Sobreira Silva
authors.initials: MS
authors.lastname: Araújo
authors.forename: Eduardo Antonio Ferraz
authors.initials: EA
authors.lastname: Coelho
authors.forename: Denise
authors.initials: D
authors.lastname: da Silveira-Lemos
authors.forename: Alexandre Barbosa
authors.initials: AB
authors.lastname: Reis
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood* / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D004283:Dog Diseases / Q000175:diagnosis* / Q000469:parasitology; D004285:Dogs; D005260:Female; D005434:Flow Cytometry / Q000379:methods / Q000662:veterinary*; D018314:Leishmania infantum / Q000276:immunology / Q000302:isolation & purification*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D008297:Male; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000662:veterinary*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan